Re: Troubles with ASN generated code

[Graham Bloice <graham.bloice () trihedral com>]

I haven't looked at the specific issue, but Windows can export data from a
DLL into another DLL.

The data to be exported should be declared __declspec(dllexport), and when
it is required to be imported declared as __declspec(dllimport).

The attached zip includes a DLL (dllexport) that exports a value (myData)
along with a function (initData) to initialise the data, a second DLL
(dllimport) that imports the value and exports a function to return the
value, and a main that initialises the data with a call into the first DLL
and then retrieves the value with a call to the 2nd DLL.

Compile with:

cl /LD dllexport.c
cl /LD dllimport.c dllexport.lib
cl main.c dllimport.lib dllexport.lib

running main.exe gives the expected out value.

Normally macros would be used such that the same header file is used for
both export and import changing the __declspec() mode depending on what is
to be done via a compilation definition.  Doing this though, does preclude
doing both import and export from the same DLL.



On 20 May 2017 at 22:03, Jaap Keuter <jaap.keuter () xs4all nl> wrote:

> On 19-05-17 19:44, Guy Harris wrote:
> > For example, if libwireshark exports a value_string table, I'm not sure
> all the platforms we support would allow a plugin dissector to point to
> that value_string from one of its header fields.
>
> I think we're seeing that with TFS (true/false strings). We have a
> collection of
> them ready for use in tfs.[ch], but these appear to be unusable in
> (dissector)
> plugins on Windows.
>
> Thanks,
> Jaap
>
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-- 
Graham Bloice
Software Developer
Trihedral UK Limited

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